Cyclone Nisarga: Landfall expected over Raigad district on Wednesday afternoon
The developing severe tropical cyclonic storm Nisarga in the Arabian Sea is expected to make landfall in Raigad district, located south of Mumbai, by Wednesday afternoon, India Meteorological Department (IMD) authorities said on Tuesday morning.
However, private weather forecasters maintained that the landfall would be in Palghar, located north of Mumbai, in line with their earlier predictions.
The weather system, currently a deep depression, is located about 280 kilometres (km) west-southwest of Panjim, 490 km south-southwest of Mumbai, and 710 km south-southwest of Surat. It is likely to intensify into a cyclonic storm by 11:30 am on Tuesday and a severe cyclonic storm in another 12 hours.
The maximum wind speed is expected to range between 100 and 110 km per hour (kmph) on Wednesday afternoon gusting to 120 kmph along the coast of Mumbai during landfall.
“The current trajectory of the system shows landfall in Raigad district just brushing south of Mumbai, which is likely to impact the country’s financial capital with the possibility of extremely heavy rain and high-speed winds,” said Sunitha Devi, in-charge of cyclones, IMD.
“The district authorities in Mumbai, Thane, Raigad and Palghar have been warned about the severity of the weather event, as Nisarga moves closer to landfall on Wednesday afternoon,” she added.
On Monday morning, the IMD authorities had expected the landfall in Palghar district, but based on studying the trajectory of the system revised their prediction by Monday evening.
Skymet, a private weather forecasting agency, on Tuesday, said the landfall is still expected in Palghar district.
“Our weather models are showing the landfall north of Mumbai with a crucial period of extremely heavy rain and gale winds expected from Tuesday evening to Wednesday afternoon,” said Mahesh Palawat, vice-president (meteorology and climate change), Skymet. “Heavy rain over Mumbai may lead to intense flooding,” he added.
IMD’s latest bulletin issued warnings for the expected storm surge and damage across Mumbai, Thane, Raigad and Ratnagiri districts on Wednesday. “Storm surge of about one-two metres high above astronomical tide (tidal characteristics associated with gravitational effects) is likely to inundate low-lying areas of Mumbai, Thane and Raigad districts, and up to one metre high above the astronomical tide likely to inundate the low-lying areas of Ratnagiri district during landfall,” the IMD release said.
Major damages are expected for thatched houses, huts and those with unattached metal sheets as rooftops, which could be blown away due to high-speed winds, the IMD bulletin said. Power and communication lines are expected to be damaged along with uprooting of trees and breaking of tree branches. Coastal crops would bear the brunt, embankments might get eroded, the IMD has warned.
Dr. Roxy Mathew Koll, senior scientist, Indian Institute of Tropical Meteorology, Pune, said if landfall occurs in Raigad, maximum rainfall is expected over northern regions, including Mumbai.
“The forecasts indicate heavy rain up to 200 millimetres (mm) while the Indian National Centre for Ocean Information Services has forecasted storm surges with waves rising up to six metres, as the cyclone approaches landfall,” he said. “If this happens during high tide on Wednesday, then flooding will be a major concern for Mumbai, which is already clogged and bursting at its seams.”
Dr. Koll pointed out that natural defences such as mangroves and river flood plains had been constructed in many parts of Mumbai for infrastructure and real estate projects and that may cause prolonged inundation concerns.
How the forecasts changed over the last three days
Cyclone Nisarga to develop in the Arabian Sea, heavy rain alert for Mumbai coast for Wednesday and Thursday. A red alert issued for the entire Konkan coast for Wednesday and Thursday. IMD, Mumbai, issued rainfall warnings in the form of an orange alert (be prepared -- heavy to very heavy rain) for Mumbai and Thane, and a red alert (take action --- extremely heavy rain) for Palghar district on Wednesday and Thursday.
Monday: Tropical cyclonic storm in the Arabian Sea likely to make landfall in Palghar district, located 100-km north of Mumbai with impact across the Union Territory Daman in south Gujarat to Harihareshwar in Raigad. Damages are expected across four districts --- Mumbai, Thane, Palghar and Raigad -- in north Konkan, as landfall is expected on Wednesday evening or at night. A red alert is sounded in all the four districts and also for Nashik, Dhule and Nandurbar for Wednesday.
Tuesday: Developing tropical cyclone in the Arabian Sea is expected to make landfall by Wednesday afternoon in Raigad district just brushing past south of Mumbai. Storm surges and damages identified. The severe cyclonic storm may lead to extremely heavy rains in Mumbai, Thane, Palghar and Raigad with high-speed winds gusting to a maximum of 120 kmph along the coast.